F TAGINI¹, T PILLONEL¹, S ASNER², G PROD’HOM¹, G GREUB<sup>1

1</sup>Institute of Microbiology, Department of Laboratory, University of Lausanne & University Hospital Center, Lausanne, Switzerland, ²Unit of Pediatric Infectious Diseases and Vaccinology Unit, Department of Paediatrics, University Hospital Center, Lausanne, Switzerland

Cardiobacterium hominis, a member of the HACEK group (Haemophilus species, Aggregatibacter species, C. hominis, E. corrodens and Kingella species) is commonly encountered in the oral and nasal human floral. HACEK group bacteria are fastidious and Gram-negative organisms of infective endocarditis. This strain was isolated from a blood culture drawn from a 4-years old child hospitalized at the University Hospital Center, Lausanne, Switzerland. The patient presented with a complex congenital cardiopathy, which required extensive cardiac surgery with insertion of prosthetic material 3 years prior to this event. He was successfully treated with ceftriaxone for 6 weeks and gentamicin for 3 weeks concomitantly. Cardiac prosthesis material was replaced 1 month after discharge. De novo assembly was done using SPAdes Genome Assembler 3.6.2. Annotation was performed using the RAST version 2.0. We searched for antibiotic resistance genes with ResFinder 2.1 and for phage sequences with PHAST. We determined identity between translated coding sequences (CDSs) and corresponding proteins on NCBI database using CLUSTALW. Sequencing produced 2’456’795 150bp-paired-end reads that were assembled into 145 contigs, with 84 contigs of >1000bp. After removal of contigs of <300bp, the total contigs size is 2’655’628bp for a G+C content of 59.0%. RAST system identified 9 putative CDSs for multidrug resistance efflux pumps that could be involved in various antibiotic resistances. However, we observed a high sensitivity to ceftriaxone and gentamicin on the antibiotic sensitivity test and no other resistance genes were found with ResFinder. Interestingly, we noticed a gene encoding for an adhesin, sharing 88.6% identity with other gamma-proteobacteria and 45.9% identity with E. corrodens, another agent of infective endocarditis. Three incomplete phage sequences were found and one of them might still be active because an integrase is located at a distance of 5 open reading frames (=1884bp) from the last phage-associated protein. To conclude, this draft genome sequence will be helpful for further genomic comparison aiming at better understanding C. hominis biological and pathogenic features.